The research program is designed to elucidate the neurobehavioral mechanisms underlying feeding behavior in birds. Pigeons are used as subjects because they are an ideal preparation for the analysis of sensory-neural interactions in feeding, permit the dissociation of feeding and drinking mechanisms, of motivational and sensori-motor mechanisms, and of hypothalamic and extra-hypothalamic mechanisms. A combination of anatomical, electrophysiological and neurobehavioral techniques will be used to determine the contribution to the neural control of feeding of structures at several levels of the avian brain. Some of the structures involved have been homologized, on morphological grounds, with a number of "limbic" and striatal regions in the mammalian brain. It is hoped that the present research will contribute to our understanding of the evolution and functional organization of these important brain regions. Furthermore, the analysis of neural control of feeding in birds may clarify some persistent neurobehavioral problems in the study of mammalian feeding behavior and thus contribute to the development of a comparative psychobiology of motivation.